1. Field of the Invention
The invention herein relates to stationery and office supply products. More particularly it relates to note and tape products which adhere to surfaces by releaseable adhesives.
2. Description of the Prior Art
One of the most popular stationery or office supply products is the adhesive-backed paper sheet or "note." The adhesive is applied to one side of the note and has only a limited degree of tackiness or adhesiveness, so that the note can be attached to a substrate, typically a piece of paper or other smooth surface, and subsequently removed without damaging the paper, surface or other substrate to which it was attached. A number of different commercial vendors market products of this type in a variety of sizes, shapes and colors; typical examples are the products marketed by 3M Company under the trade name "Post-It". The note sheets are commonly sold in padded form, with the adhesive on the back of one sheet adhering to the adhesive-less face of the next sheet below it in the pad. The user then peels a single sheet or note off of the pad and sticks it to a sheet of paper or a surface as desired. However, while these note sheets are widely used and are very useful for many purposes, they have one major limitation: since they are "single-sided," they can only be used as single sheets. Their sole capability is to serve as a note or marker itself; they have no capability of being used in conjunction with more than a single substrate to which they may be attached.
(As used herein, the terms "single-sided" and "double-sided" will refer to the location(s) of adhesive on a note or sheet product, and thus to the producers capability for adherence to other surfaces. A "single-sided" product has adhesive only on one principal side, and therefore can adhere to only one other surface, while a "double-sided" product has adhesive on both principal sides and can adhere to two surfaces simultaneously.)
There have also been "double-sided" adhesive products, commonly tapes, available in the marketplace. These are normally formed as a length of clear film with single type of adhesive covering both sides. In essence they are nothing more than conventional clear "cellophane" tape but with adhesive on both sides instead of on only one side. The adhesives used are conventional non-releaseable tape adhesives, so they securely join the two substrates to which they are adhered and cannot be removed without damage to one or both of those substrates, especially where a substrate is a paper or painted surface.
Double-sided tape products have been marketed which are formed with a higher tack adhesive on one side and a lower tack adhesive on the other side. These have proved to be of very limited utility, however, for several reasons. Commonly the higher tack adhesive has been of only very limited releaseability and has had a tendency during separation attempts to tear or otherwise damage the substrate from which it is being separated, especially if that substrate is a relatively fragile material such as paper and one tries to perform the separation reasonably quickly. Also, since the tapes and both adhesives are normally clear, there is no way to differentiate the two sides visually, so that users have great difficulty adhering the tape to the respective substrates properly. Finally, for such tapes to be rolled, one must use a separation sheet between each layer to prevent the two adhesives from contacting each other, which is both inconvenient for the user and creates a substantial amount of waste material which must be disposed of.
There are no known commercial releaseable double-sided notes, tapes or sheets, especially ones which can be obtained in padded or rolled form without divider sheets. Conventional double-sided tapes are not releaseable, and therefore cannot be used for creating double-sided notes as by attaching them to bare sheets of paper. Further, simply double-siding conventional single-sided releaseable notes and tapes does not produce a useful product, since two conventional adhesive bonds formed with two opposing surfaces will not separate in a predictable manner. Since the adhesives are aligned and alike on both sides, one attempting to peel apart two surfaces joined by a double-sided product would find that half the time the double-sided joining product would, separate from one sheet's surface and half the time from the other. In addition, if such double-sided notes are stacked upon one another, contact between the adhesive of the note above and that of the note below increases the amount of force required to separate the notes, causing unwanted paper curl and reduced ease of use.